In quality control instances, particularly in quality control of printed images, it may be typical to quantitatively assess the amount of grain, i.e. extent of graininess, e.g., the extent to which the image, or an image of a substance appears to be composed of grain-like particles, and/or amount of mottle, i.e. mottledness, e.g., spotty or patchy color within an image.
In some examples, it may be desired to assess graininess and mottledness in the field, or on the manufacturing floor, where a dedicated measurement device is not immediately present, and when results need to be found immediately.
One way to assess graininess is human metrology. However, in the field, on a short notice, and with untrained personnel, there may be some use for a standardizable machine vision approach.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.